Recommending users to add to groups in a social networking system

ABSTRACT

Based on information associated with users, a social networking system recommends one or more groups for a target user to join or to create. Characteristics of the target user, characteristics of users connected to the target user, characteristics of candidate groups in the social networking system may be used to identify groups for recommendation. The social networking system may provide questions to the target user and recommend a group to the target user based on received answers to the questions. For example, the answers to the provided question identify one or more characteristics of the target user, which are used to select a group for recommendation. Additionally, the social networking system may recommend additional users for the target user to add or invite to a group based on characteristics of the target user, the additional users, and/or the group.

BACKGROUND

This invention relates generally to social networking and, inparticular, to recommending groups for a target user to join or create,and to recommending other users for the target user to add to a group.

Automatically organizing social networking system users into groups ofassociated users can be an inefficient process subject to mistakes.Social networking systems may have up to hundreds of millions of usersor more, so selecting the most relevant groups for each user is aresource-intensive process. Large numbers of social networking systemusers also make the manual organization of groups by the user atime-consuming process, and may result in the user failing to identifythe groups most relevant to the user. Thus, the time needed by users tomanually identify relevant groups makes it likely that certain users donot join groups that they otherwise would join. Further, requiringmanual group selection may discourage a user from creating a new groupbecause of the time involved in adding users to a created group.Simplifying the identification of groups for users to join, theidentification of users to add to groups and the creation of groupsallows social networking system users to better identify groups of otherusers with similar interests, improving overall user interaction withthe social networking system.

SUMMARY

A social networking system provides group recommendations to its users.For example, the social networking system provides a target user with arecommendation of a group to join. The target user may explicitlyrequest a recommendation of a group to join or may access a portion ofthe social networking system associated with group recommendations. Torecommend a group to the target user, a set of users connected to thetarget user is first identified. The set of users connected to thetarget user can be users that have explicitly established a connectionwith the target user within the context of the social networking system,or can be users having one or more characteristics in common with thetarget user.

Based on the set of users connected to the target user, a set ofcandidate groups for recommendation is identified from a plurality ofgroups stored at the social networking system. In one embodiment, theset of candidate groups includes at least a set of groups having usersfrom the identified set of users connected to the target user asmembers. A candidate group is selected from among the set of candidategroups based on one or more of: the characteristics of the users in theset of users connected to the target user, the characteristics of thetarget user, and the characteristics of the set of candidate groups. Forexample, a candidate group is selected based on the level of activity ofusers within the candidate group and based on the strength of theconnection between the target user and various users within thecandidate group. The selected candidate group is presented to the targetuser to allow the target user to easily join the selected candidategroup. For example, the selected candidate group is displayed to thetarget user using a group recommendation interface. Alternatively, thesocial networking system may automatically add or invite the target userto the selected candidate group.

In one embodiment, a group is selected from the candidate groups basedon candidate scores computed for each candidate group. Candidate scoresmay be based on a level of activity of users in a candidate group, onaffinities between the target user and the users in a candidate groupand/or any other characteristic associated with the target user, withusers in a candidate group, and/or with a candidate group. Additionalfactors may be used to modify candidate scores. Example factors include:the size of candidate groups, characteristics common to the target userand a candidate group, characteristics common to the target user andusers within a candidate group, whether associated candidate groups areopen or closed, based on the size of the candidate groups, or any othersuitable criteria.

In addition to recommending one or more groups for a user to join, thesocial networking system may also simplify group creation by identifyingadditional users to a user creating a group. For example, a user maycreate a group and the social networking system identifies users to addto the group. A user, such as a user creating or administering a group,selects a target group. For example, the user is included in the targetgroup or created the target group. A set of candidate users isidentified by the social networking system and characteristics of thecandidate users are identified. For example, the set of candidate usersincludes users connected to the user selecting the target group and/orusers having one or more characteristics in common with the userselecting the target group.

Based on the characteristics of the candidate users, a candidate user isselected to recommend for addition to the target group. For example, theselected candidate user is the candidate user having the most commonconnections with the user selecting the target group or is the candidateuser connected to the highest number of users in the target group.Alternatively, a user score is generated for each of the candidate usersbased on characteristics of a candidate user, the user selecting thetarget group and/or the target group. One or more candidate user isselected based on the user scores. For example, a user score for acandidate user is based on one or more of: the affinity between thecandidate user and the user selecting the target group, the likelihoodof the candidate user joining the target group if invited, thelikelihood of the user selecting the target group inviting the candidateuser if suggested or any other suitable factor. One or more candidateusers are selected and displayed to the user selecting the target group,allowing the selected candidate users to be invited to the to the targetgroup. Alternatively, selected candidate users may be automaticallyinvited to or added to the target group.

The social networking system may also suggest a group for creating byidentifying one or more characteristics common to multiple users,simplifying the creation of a group including users having a commoncharacteristic. A creating user may be a user that requests arecommendation of a group to create, or may be otherwise identified bythe social networking system. A set of users associated with thecreating user is identified. For example, the set of users includesusers connected to the creating user or having one or morecharacteristics in common with the creating user.

A characteristic common to the target user (a “common characteristic”)and to one or more users in the set of users is selected. In oneembodiment, the common characteristic is a characteristic shared by thecreating user and the highest number of users in the set of users, ahighest priority characteristic shared by the creating user and one ormore users in the set of users, or a characteristic shared by thecreating user and users in the set of users having the highestaffinities with the creating user. Examples of a common characteristicinclude a geographic characteristic, a biographic characteristic, aninterest, a hobby, a political viewpoint, a religious viewpoint, aphilosophy, or any other suitable information included in user profiles.

A group associated with the selected common characteristic isrecommended to the creating user. In one embodiment, a recommendationfor the group includes a title for the recommended group based on theselected common characteristic and one or more users from the set ofusers having the selected common characteristic. Alternatively, therecommendation for the group identifies the selected commoncharacteristic, allowing the creating user to identify users to includein the recommended group, such as using a customization interface. Inanother embodiment, the recommended group is automatically created andassociated with a title based on the selected common characteristic.

To more accurately recommend a group for a target user to join, thesocial networking system may present one or more questions to the targetuser and determine a recommended group based on answers to the questionsreceived from the target user. The questions may be selected to identifyparticular characteristics associated with the target user. Examples ofcharacteristics identified by the questions include: geographiccharacteristics, biographic characteristics, hobbies, interests,political viewpoints, religious viewpoints, philosophies, or othersuitable characteristics. In one embodiment, the questions presented tothe target user are selected by the social networking system based onone or more of: the context of the target user within the socialnetworking system, characteristics associated with the target user, oneor more other groups in the social networking system including thetarget user, characteristics of other users connected to the targetuser, or similar information.

The target user may provide answers to the questions using any suitableinterface. For example, predefined answers are presented to the targetuser along with a question, allowing the target user to select an answerfrom the predefined answers. Predefined answers may be associated withparticular groups or with particular subject matter associated withgroups. As another example, the target user enters text to provide ananswer to a presented question. Candidate groups are identified based onthe received answers. For example, answer text is compared to keywordsassociated with stored groups and groups associated with one or morekeywords matching answer text are identified as candidate groups. Fromthe candidate groups, a group is selected for recommendation to thetarget user and the selected group is presented to the target user. Agroup may be selected based on one or more of: the size of the group,the date the group was created, the number of users connected to thetarget user included in the group, one or more characteristics of thegroup, one or more characteristics of the target user, affinitiesbetween the target user and users in the group, an affinity between thetarget user and the group or any suitable criteria. In one embodiment,if a stored group is not associated with the received answers, thesocial networking system recommends that the target user create a groupassociated with the received answers. While the target user may beautomatically added to the selected group, the selected group mayinstead be identified to the target user, allowing the target user tojoin the group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a high-level block diagram illustrating the recommendation ofgroups for a social networking system user to join, to create, or to addother users, in accordance with an embodiment of the invention.

FIG. 2 is a network diagram of a system environment for recommendinggroups to a user, in accordance with an embodiment of the invention.

FIG. 3 is a flowchart of a process for recommending a group for a socialnetworking system user to join, in accordance with an embodiment of theinvention.

FIG. 4 is a flowchart of a process for selecting a user to recommend toadd to a group in a social networking system, in accordance with anembodiment of the invention.

FIG. 5 is a flowchart of a process for recommending a group for a socialnetworking system user to create, in accordance with an embodiment ofthe invention.

FIG. 6 is a flowchart of a process for recommending a group for a socialnetworking system user to join based on the answers by the user to oneor more questions, in accordance with an embodiment of the invention.

The figures depict various embodiments of the present invention forpurposes of illustration only. One skilled in the art will readilyrecognize from the following discussion that alternative embodiments ofthe structures and methods illustrated herein may be employed withoutdeparting from the principles of the invention described herein.

DETAILED DESCRIPTION

Overview

A social networking system offers its users the ability to communicateand interact with other users of the social networking system. Usersjoin the social networking system and add connections to a number ofother users to whom they desire to be connected. Connected users aresaid to be “friends” in the context of the social networking system. Asocial networking systems comprises a series of interconnected pages,which may be displayed in a web browser or native application on aclient device. Users of a social networking system can provideinformation describing themselves, which is stored in user profiles.Content from a user profile may be displayed in an associated profilepage. For example, a user can provide information about its age, gender,geographical location, education history, employment history, hobbies,interests, favorite movies, favorite music, favorite books, religiousviews, political views, and other similar descriptive information.Information may be directed to the user by the social networking systembased on the information provided by the user. For example, the socialnetworking system may recommend articles, events, and potential friendsto a user based on the user's user profile. Collectively, informationassociated with the user (such as information entered by the user),actions taken by the user, users connected with the user, groups joinedby the user, and the like are referred to herein as “characteristics” ofthe user.

Information tracked and maintained by a social networking system is usedto create a social graph, which includes a plurality of nodes that areinterconnected by a plurality of edges (representing interactions,connections, communications or other measures of relatedness betweennodes). A social graph node may represent a social networking systemobject that may act on and/or be acted upon by another object having acorresponding node. An edge between nodes in a social graph representsany kind of connection or interaction between the two nodes, which mayresult from an action that was performed by one of the nodes on theother node. For example, two users connected in a social networkingsystem may each be represented by nodes in the social graph, with anedge connecting the nodes representing the connection between the users.Likewise, a user may “check-in” to a physical location, such as a sportsbar, using a device with location-detection functionality (such as amobile phone with GPS functionality), and the user and sports bar areeach represented by nodes in the social graph that are connected by anedge representing the user's “check-in” to the sports bar.

The edges in the social graph may be organized into various categories.For example, one subset of edges represents established connectionsbetween users, another subset represents users indicating a preferencefor a social networking system object (“liking” the object), anadditional subset represents “checking in” to a particular location by auser, and so forth. Subsets of edges may be broken down into furthersubsets of edges as well. For example, the subset of edges representingestablished connections between users is broken into a subset of edgesrepresenting family connections between users, a subset of edgesrepresenting friend connections between users, a subset of edgesrepresenting co-worker connections between users, and the like.

Edges in the social graph may be associated with affinity scoresrepresenting the importance, strength, or relevance of connectionsbetween objects. The affinity scores may be referred to as “affinities”or “coefficients.” The affinity associated with an edge may berepresented in any suitable format such as numeric weights, non-numericweights (high, medium, low, etc.), Boolean weights, and the like. In oneembodiment, different types of edges are associated with an affinityrepresenting the relevance of a node to an additional node connected tothe node. For example, family relationships between users may be morerelevant than co-worker relationships between users; accordingly, edgesrepresenting family connections may be associated with a higher weightthan edges representing co-worker connections. As another example, edgesrepresenting a user joining a group may have a higher affinity thanedges representing the posting of a message to the group's wall by auser not included in the group if joining a group is determined to bemore relevant than the posting of a message to the group's wall by auser not included in the group.

Affinities between objects may be used to infer the relevance of anobject's characteristics to another object. For example, if a first user(represented by a first node) is connected to a second user (representedby a second node) with an edge associated with a high affinity and isalso connected to a third user (represented by a third node) with anedge associated with a lower affinity, an action taken by the seconduser may be inferred to be more relevant to the first user than anaction taken by the third user. Nodes may be connected by multipleedges. For example two users may be connected by an edge representing afamilial relationship, an edge representing a tagging of a user in aphotograph by the other user, another edge representing a message from auser to the other user, and so forth. If multiple edges connect twonodes, a combination of the affinities associated with each node may beused to infer the relevance of one node to the other. For example, theaverage, weighted average, sum, weighted sum, or other combination ofthe affinities associated with the edges may be used to make inferencesabout the relevance of the characteristics of nodes connected to eachother by multiple edges. For simplicity, discussion of inferringrelevance between nodes herein refers to a single affinity associatedwith an edge between nodes, although this single affinity may representthe combination of multiple affinities associated with multiple edgesbetween nodes.

Affinities can be based on the number or type of interactions betweentwo nodes, can be based on the amount of characteristics in commonbetween two nodes, can be based on a common node to which each of twonodes is connected, and can be based on any other suitable factor.Affinities can be determined as described in U.S. patent applicationSer. No. 12/978,265, titled “Contextually Relevant Affinity Predictionin a Social Networking System,” filed Dec. 23, 2010, the contents ofwhich are incorporated herein by reference in their entirety.

Information stored in the social graph may be queried to identifyassociated sets of information. For example, a root node in the socialgraph is identified and nodes connected to the rood node are identified(e.g., all nodes connected to the root node, a subset of nodes connectedto the root node, one or more individual nodes connected to the rootnode, etc.). A particular node is connected to the root node if an edgeconnects the particular node to the root node. As an example of a queryto the social graph, a particular user is identified as the root node,edges connecting to the root node are identified, and nodes connected tothe identified edges are identified. Continuing with this example, toidentify users connected to the user associated with the root node, onlythe nodes connected to the root nodes by edges representing connectionsbetween users are identified. In one embodiment, the social graph can bequeried using two nodes to determine if an edge connects the nodes.

A social networking system allows its users to form groups, whichinclude one or more users and are associated with particular subjectmatter or characteristic. Users included in a group are referred to as“members” of the group or “group members.” In many embodiments, thesubject matter associated with a group is an interest, association,characteristic, or affiliation common to members of the group. Examplesof subject matter associated with a group include biographic orgeographic information common to group members (for instance, a commonworkplace, school, class year, current location, hometown, and thelike); a hobby, an interest (a favorite sport or sports' team, anactivity, celebrity, and the like), an art, an artist, an entertainmentformat (a movie, actor, band, music, music genre, book, author, videogame, board game, and the like), a political view, a religious view, aphilosophy, a concept, or any other suitable characteristic common to aplurality of users. The subject matter of the group, the communicationswithin the group, the members of the group, and the like are referred toherein as “characteristics” of the group.

To aid users in identifying groups and/or to obtain information aboutusers, the social networking system may present questions to users andstore the answers received from users. The social networking system orusers of the social networking system may identify the questionspresented to other users. For example, a question interface displays aquestion and one or more selectable answers and/or provides an inputthat allows a user to create a text answer. Information about a questionmay also be presented. Examples of information about a question include:the percentage or number of answering users that have selected eachanswer, the identity of the questioning or any answering user, and thelike. Questions may be presented in a sequence dependent on the receivedanswers so that an answer to a question is used to select a subsequentquestion. For example, a user may answer the question “Where do you goto school?” with the answer “Stanford University,” so the socialnetworking system subsequently asks “What major are you?”

Pairs of questions and answers may be associated with a particularsubject matter or a particular group. In one embodiment, a user canassociate a question or answer with a particular subject matter using atag or data field associated with the question or answer. In the socialgraph, a node represents the question and additional nodes representeach answer. The nodes representing the question and one or more nodesrepresenting answers to the question may be connected to nodesrepresenting one or more of: the questioning user, any answering user,subject matter associated with the question or an answer, a groupassociated with the question or an answer, and the like.

A social networking system user may explicitly join a group or may beautomatically added to a group based on information provided by the userto the social networking system. Groups can be “open,” allowing anyoneto join, or “closed,” requiring a user to request to join or be invitedby an existing group member to join. Hence, a user is unable to join a“closed” group until addition of the user to the group is approved, forinstance by a group manager, and/or the user provides credentials (suchas an email address from a particular domain, a password, or the like).A group may have a dedicated page in the social networking systemserving as an information hub for group members to access one or moreof: information about the group, group events, a group calendar, groupphotos, other group members, group documents, and any other groupfeatures. In some instances, all or part of the information accessiblevia the group page is visible only to members of the group.

A group page may provide one or more interfaces for group members tocommunicate with each other. For example, a group page includes amessage board or wall allowing group members to post messages viewableby all or a subset of the group members. A group page may also have aninstant messaging, video messaging, or email messaging interfaceallowing group members to communicate. In one embodiment, a group isassociated with an email address that forwards received emails to groupmembers, acting as a mailing list for communicating with group members.

A social networking system may allow any user to create a group. In oneembodiment, a user provides information for creating a group using aspecified form. Social networking system users may add other users to agroup. Users may opt out of a group to which they are added, or mayrequire that they approve of any group to which they are added by otherusers prior to being added to the group. In one embodiment, if a useropts out of a group, the social networking system prevents other usersfrom re-adding the user to the group without pre-approval from the user.

Groups may be organized hierarchically by the social networking system.For example, one group is a top-level group representing an entity (forinstance, a group representing the University of Utah), a first set ofsub-groups represents various departments of the entity (for theUniversity of Utah example, a first sub-group can represent sports, asecond sub-group can represents academics, a third sub-group canrepresent students, etc.), a second set of sub-groups representsdivisions of the departments (for example a sub-group representingsports includes a basketball sub-group, a baseball sub-group, etc.), andso forth. For a group including one or more sub-groups, the group isreferred to as a “parent group,” and the sub-groups are referred to as“child groups.” A child group is a parent group for sub-groups includedin the child group. In one embodiment, when groups are organizedhierarchically, a user may be required to be a member of a parent groupbefore the user may join a child group of the parent group.

Groups are represented in the social graph by a node. A noderepresenting a user that is a member of a group is connected to the noderepresenting the group by an edge representing the association of userwith the group. Additional edges between a node representing a user anda node representing a group may be established to identify interactionsbetween the user and the group. For example, the node associated with auser is connected to the node representing a group by an edgerepresenting a communication to the group from the group member, and anynumber of additional edges representing other interactions between thegroup member and the group may be added. The group node may also beconnected to a node representing the group's subject matter.

FIG. 1 is a high-level block diagram illustrating the recommendation ofgroups for a social networking system user to join, to create, or to addother users, in accordance with an embodiment of the invention. Theexample of FIG. 1 shows a target user 105 interacting with a socialnetworking system 100. The social networking system 100 includes a userinterface 110, a group recommendation engine 120, and storage 160including a social graph storage module 165 and a group storage module170. Data from the target user 105 is received by the social networkingsystem 100 via the user interface 110, which also presents the targetuser 105 with one or more group-related recommendations from the grouprecommendation engine 120.

The group recommendation engine 120 recommends one or more groups forthe target user 105 to join based on information about the target userand other users stored in the social graph store 165 and/or informationassociated with one or more candidate groups stored in the group store170. In various embodiments, the group recommendation engine 120 may useany additional information when recommending groups to the target user105. The target user 105 may be prompted to join a recommended group viathe user interface 110. Alternatively, the group recommendation engine120 automatically adds the target user to a recommended group andnotifies the user of its addition to the recommended group.

In addition to recommending existing groups for the target user 105 tojoin, the group recommendation engine 120 may also recommend a new groupfor the target user 105 to create. Information in the social graph store165 associated with the target user, associated with users connected tothe target user 105, and/or any other suitable information in the socialgraph store 165 may be used to recommend a group for the target user 105to create. For example, from information in the social graph store 165,the group recommendation engine 120 determines the target user 105 is aBerkeley alumni, the target user 105 is a fan of the rock group Poison,and that the target user 105 is connected to several additional usersthat are Berkeley alumni and are fans of Poison. Hence, the grouprecommendation 120 engine may recommend that the target user 105 createa “Berkeley alumni Poison fan club” group. Further, the grouprecommendation engine 120 may recommend one or more groups for thetarget user 105 to join or to create based on answers received from thetarget user 105 in response to a set of questions.

Additionally, the group recommendation engine 120 may recommend one ormore users for the target user 105 to add to one or more groups. Thegroups may be a group including the target user 105 as a member, or agroup otherwise associated with the target user 105 or associated withan identified user connected to the target user 105. Data in the socialgraph store 165, data in the group store 170, or any other informationin the social networking system 100 associated with the target user 105or with users connected to the target user 105 may be used to recommendusers for addition to a group associated with the target user 105.Operation of the group selection module 120 is further described belowin conjunction with FIGS. 2-6.

FIG. 2 is a network diagram of a system environment 200 for recommendingactions associated with groups to a user, in accordance with anembodiment of the invention. The system environment 200 includes atarget user 105 communicatively coupled to a social networking system100 via a network 202. The target user 105 is associated with a clientdevice (e.g., a smart phone, a laptop computer, a desktop computer,etc.), which receives input from the target user 105 and communicatesthe data to social networking system 100 via the network 202. The clientdevice also receives data from the social networking system 100 via thenetwork 202 and presents the data to the target user 105. The network202 may be a local area network, a wide area network, or any othernetwork or combination of networks that allows communication betweendevices. The connecting network may use standard communicationstechnologies and/or protocols and may include wireless and/or wiredcommunication protocols. In other embodiments, the system environment200 includes additional components not illustrated herein.

The social networking system 100 includes a user interface generator205, a web server 210, a join group recommendation module 220, a userinvitation module 230, a group creation recommendation module 240, and agroup question module 250. In one embodiment, the group recommendationmodule of FIG. 1 includes the join group recommendation module 220, theuser invitation module 230, the group creation recommendation module240, and the group question module 250. The social networking system 100also includes the social graph store 165 and the group store 170 shownin FIG. 1. In other embodiments, the social networking system 100includes additional, fewer, or different components than thoseillustrated herein.

The target user 105 communicates with the social networking system 100via the network 202. As described above, the target user 105 users aclient device to communicate with the social networking system 200.Examples of client devices include a mobile phone, laptop computer,desktop computer, netbook, tablet computer, cable box, or anothersimilar device. An application running on a client device, such as a webbrowser or native application, communicates data between the clientdevice and the social networking system 100 and allows the target user105 to interact with content stored by the social networking system 100.For example, an application operating on a client device allows thetarget user 105 to browse content, post and send communications,establish connections with other users, join groups, create groups,invite other users to join groups, answer questions, or perform otherinteractions with content on the social networking system 100.

The web server 210 manages receiving and transmitting communications toand from the social networking system 100 via the network 202, andformats communications based on requirements or specifications of thenetwork 202, client devices and/or user preferences. The web server 210receives data from components of the social networking system 100describing content and formatting of pages including information storedand/or maintained by the social networking system 100. In oneembodiment, the web server 210 receives a user interface generated bythe user interface generator 205 and communicates instructions forgenerating the user interface to a client device of the target user 105for presentation. The web server 210 also receives data from the targetuser 105 via the user interface and directs the received data tocomponents within the social networking system 100.

The user interface generator 205 generates instructions and/or data forpresenting a user interface to social networking system users. Throughthe user interface, social networking system users exchange data withthe social networking system 100 and otherwise interact with the socialnetworking system 100. For example, the user interface generator 205produces instructions that, when executed by a client device, produce agraphical user interface allowing users to navigate content stored bythe social networking system 100. The user interface generator 205 maygenerate forms and/or pages for a user to enter biographic or geographicinformation, to establish connections with other users, to uploadcontent, to join groups, to invite other users to groups, to creategroups, to answer questions, and the like. Other components of thesocial networking system 100, such as the join group recommendationmodule 220, the user invitation module 230, the group creationrecommendation module 240, and the group question module 250,communicate with the user interface module 205 to present group-relatedrecommendations to the target user 105 in a user interface, which alsoallows the target user 105 to interact with the presentedrecommendations. In one embodiment, a generated user interface has aportion dedicated to group-related recommendations. Alternatively, theuser interface generator 205 generates a page including group-relatedrecommendations.

Recommendations to the target user 105 relating to a group, which arefurther described below, may be generated in response to a request for arecommendation from the target user 105, in response to actionsperformed by the target user 105, or may be automatically generated. Forexample, the target user 105 interacts with portions of a user interfaceto request a group-related recommendation. As another example,recommendations of additional users to join a group or questions foridentifying additional groups are presented to the target user 105 inresponse to a target user 105 joining the group.

Recommending a Group to Join

The join group recommendation module 220 recommends one or more groupsidentified from the group store 170 for the target user 105 to join. Therecommended one or more groups are determined based on characteristicsof users connected with the target user 105, characteristics of groupsin the group store 170, characteristics of the target user 105, and/orother information stored by the social networking system 100. Torecommend a group, the join group recommendation module 220 identifies aset of one or more users connected to the target user 105 from thesocial graph store 165. In one embodiment, the set of users includes oneor more users that have explicitly established a connection with thetarget user 105. In an alternative embodiment, the set of users includesone or more users sharing a common characteristic with the target user105. Examples of common characteristics between the target user 105 andusers in the set of users include biographic characteristics, geographiccharacteristics, demographic characteristics, interests, politicalviews, religious views, one or more common social networking systemgroups, and the like.

The join group recommendation module 220 retrieves an affinity betweenthe target user 105 and each of the users in the set of users from thesocial graph store 165. In one embodiment, an affinity between thetarget user 105 and a user is represented by a coefficient thatrepresents the strength of the connection between the user and thetarget user 105. Affinities between users are further described above.Based on the identified set of users, the join group recommendationmodule 220 identifies a set of candidate groups. In one embodiment, thejoin group recommendation module 220 accesses the social graph store 165to identify groups having at least a threshold number of users in theset of users as members. The threshold number of users allows the joingroup recommendation module 220 to modify the number of candidate groupsso that each candidate group includes a minimum number of members fromthe set of users. In one embodiment, for each combination of candidategroup and user from the set of users, the join group recommendationmodule 220 determines a level of activity of the user with the candidategroup. The level of activity indicates a frequency/and or amount ofinteraction between the user and the candidate group. For example, thelevel of activity is a coefficient associated with an identified userthat is based on interactions between the identified user and acandidate group, interactions between the identified user and othermembers of the candidate group, and/or other similar interactions. Inone embodiment, the value of the coefficient is proportional to thefrequency and/or amount of an identified user's interactions with acandidate group, so a lower coefficient indicates fewer interactions andvice versa.

Alternatively, a set of candidate groups is identified by the grouprecommendation module 220 before identifying a set of users connected tothe target user 105. In such an embodiment, a set of candidate groupssharing one or more common characteristics with the target user areretrieved from the group store 170. For example, if the target user 105lists the movie “Shawshank Redemption” as a favorite movie in a userprofile, the group storage module 170 is accessed to identify groupsassociated with the movie “Shawshank Redemption,” which are used as theset of candidate groups. After identifying the set of candidate groups,users that are members of at least one candidate group are identifiedfrom the group store 170 or from the social graph store 165. The socialgraph store 165 is accessed to identify which of the identified usersare connected to the target user 105.

The join group recommendation module 220 selects one or more candidategroups based on various factors. Examples of factors include:characteristics of the target user 105, characteristics of the set ofusers connected to the target user 105, and/or the characteristics ofthe set of candidate groups. In one embodiment, a candidate score iscomputed for each candidate group, and the one or more candidate groupswith the highest candidate scores are selected for recommendation. Acandidate score for a candidate group is based on one or more of: theaffinity of the target user 105 for the candidate group, affinities ofthe target user 105 for each user in the candidate group, and the levelof activity of users in the candidate group. For example, a candidatescore for a candidate group is determined by combining a product of auser's level of activity within the candidate group and the affinitybetween the target user 105 and the user in the candidate group, foreach user in the candidate group that is connected to the target user105. For example, candidate group XYZ includes three users (User A, UserB, User C) connected to the target user 105 are members of candidategroup XYZ, with the following coefficients for the three users:

User A—Target User Affinity: 0.5

User A—Group XYZ Activity: 0.4

User B—Target User Affinity: 0.7

User B—Group XYZ Activity: 0.9

User C—Target User Affinity: 0.2

User C—Group XYZ Activity: 1.5

In this example, the coefficient between User A and the target user 105representing affinity between User A and the target user 105 is 0.5, thecoefficient representing the level of activity of User A with Group XYZis 0.4, and so forth. A candidate score for Group XYZ may be computed bysumming the products of the pair of coefficients for each user. Forexample, the coefficient representing the affinity of User A and thetarget user 105 and the coefficient representing the level of activityof User A with Group XYZ are multiplied, the coefficient representingthe affinity between User B and the target user 105 is multiplied by thecoefficient representing the level of activity of User B with Group XYZ,and the coefficient representing the affinity between User C and thetarget user 105 is multiplied by the coefficient representing the levelof activity of User C with Group XYZ, and the resulting products aresummed. In this example, the candidate score for Group XYZ is:0.5*0.4+0.7*0.9+0.2*1.5=1.13.

Candidate scores may be determined in other ways. In one embodiment,candidate scores may be determined without considering the level ofactivity of users connected to the target user 105 within candidategroups. For example, a candidate score comprises the sum of affinitiesbetween members of the candidate group connected to the target user 105and the target user 105. In this embodiment, candidate groups includingmembers having high affinities with the target user 105 have highercandidate scores. Alternatively, a candidate score may be determinedbased on the number of members in the candidate group that are connectedto the target user 105.

Candidate scores can be based on a user's affinity for concepts,interests, or subject matter associated with the group. In oneembodiment, a candidate score can be based on a user's affinity towardsone or more nodes to which the candidate group are explicitly connected.The explicit connection between groups and nodes representing concepts,interests, or subject matter are further described in U.S. patentapplication Ser. No. 13/239,340, titled “Structured Objects and Actionson a Social Networking System,” filed on Sep. 21, 2011, the contents ofwhich are incorporated herein by reference in their entirety. In oneembodiment, a candidate score can be based on a connection between aninferred group topic and a concept, interest, or subject matter, usingfor instance natural language and/or keyword comparisons. Inferredtopics (described herein as “dark tagging”) are further described inU.S. application Ser. No. 12/589,693, titled “Providing Content UsingInferred Topics Extracted from Communications in a Social NetworkingSystem,” filed Aug. 20, 2012, the contents of which are incorporatedherein by reference in their entirety. Candidate scores can also bebased on a user's search queries, based on social graph nodes associatedwith such search queries, based on structured data and keywordsassociated with user communications and interactions, based on ads withwhich a user interacts, or based on any other factor associated with theuse of the social networking system 100 by a user.

In some embodiments, candidate scores are modified based oncharacteristics of the target user 105, characteristics of the usersconnected to the target user 105, and/or characteristics of thecandidate groups. For example, candidate scores may be weighted based oncandidate group type. For instance, closed groups (groups requiring aninvitation or explicit approval by a group manager) may be associatedwith lower coefficients relative to open groups (groups that anyone canjoin); hence, candidate scores associated with open groups may beadjusted upwards relative to candidate scores associated with closedgroups, and vice versa. As another example, candidate scores may beweighted based on the number of members of each candidate group. In oneembodiment, candidate scores associated with large groups are weightedupward relative to candidate scores associated with small groups.Candidate scores can be weighted based on the level of activity withineach candidate group. For example, candidate scores associated withcandidate groups having members that frequently interact with thecandidate group (e.g., members that communicate with other members, postmessages to a group wall, share content within the group, etc.) can beweighted upward relative to candidate scores for candidate groups withless-active members.

Additionally, characteristics common to candidate groups and the targetuser 105 may be used to weight candidate scores. For example, commongeographic information, biographic information, demographic information,or any other characteristic between a candidate group and the targetuser 105 may be used to modify the candidate group's candidate score.For example, candidate scores for candidate groups associated with alocation matching the current location of the target user 105 ormatching a location identified as the target user's hometown may beincreased. A candidate group's candidate score may be weighted based oncommon characteristics between the target user 105 and members of thecandidate group connected to the target user. For example, if severalmembers of a candidate group connected to the target user list a commonschool, the candidate group's candidate score may be increased relativeto other candidate scores.

One or more candidate groups selected for recommendation to the targetuser 105 are presented to the target user 105 via the user interface110. The target user 105 may choose to join a selected candidate groupor may choose not to join a candidate group by interacting with the userinterface. Alternatively, the target user may be automatically added toa selected group, or may be automatically requested to join arecommended group that is closed

FIG. 3 is a flowchart of one embodiment of a process 300 forrecommending a group for a target user to join. As described above, aplurality of groups are stored 305 by the social networking system 100,and a target user is selected 310. The target user may explicitlyrequest a recommendation of a group to join or may be any user of thesocial networking system 100.

The group join recommendation module 220 of the social networking system100 identifies 320 a set of users connected to the target user andidentifies 330 a set of candidate groups. In one embodiment, theidentified set of candidate groups having at least one member that isconnected to the target user or that has at least one commoncharacteristic with the target user. In an alternative embodiment, theset of candidate groups is identified 330 and the set of candidate usersis identified 320 based on the set of candidate groups. For example, theset of candidate groups is identified 330 and users included in at leastone candidate group and also connected to the target user or having atleast one characteristic in common with the target user are identified320.

Based on characteristics of the target user, characteristics of the setof users connected to the target user and/or characteristics of the setof candidate groups, one or more candidate groups are selected 340. Inone embodiment a candidate score is determined for each candidate groupbased on the affinities between the target user and users in a candidategroup connected to the target user and the level of activity of users inthe candidate group that are connected to the target user.Characteristics of a candidate group may be used to modify a candidategroup's candidate score. Examples of group characteristics modifying acandidate score include: whether a candidate group is open or closed,the number of candidate group members, common characteristics between acandidate group and the target user, common characteristics between thetarget user and candidate group members, and so forth. The candidatescores are used to select 340 a candidate group. For example, thecandidate group with the highest candidate score is selected 340 orcandidate groups having a candidate scores of at least a threshold areselected 340. The selected candidate group or groups are presented tothe target user via a user interface. Alternatively, the target user isautomatically added to a selected candidate group. For example, thetarget user's user profile may permit the social networking system 100to automatically add the target user to recommended groups.

As an example of the process of FIG. 3, a user requesting arecommendation of potential groups to join is selected as the targetuser. In this example, the friends of the target user within the contextof the social networking system are identified as the set of usersconnected to the target user, and the groups to which at least athreshold number of friends belong are identified as the set ofcandidate groups. For instance, if over a threshold number of friendsbelong to a “Stanford University” group, it is added to the set ofcandidate groups. Similarly, if less than a threshold number of friendsbelong to a “Duke University” group, it is not added to the set ofcandidate groups. Continuing with this example, a candidate score isdetermined for each group in the set of candidate groups. The candidatescore for each group is based on how active each friend is in eachcandidate group (for instance, an average of a measure of activityacross all friends), and based on the affinity between each friend andthe target user. In this example, the candidate group associated withthe highest candidate score is selected, and the target user ispresented with the option of joining the selected candidate group.

Recommending Users to Invite to a Group

In addition to recommending a group for a target user to join, thesocial networking system 100 may aid members of a group in invitingadditional users to join the group. For example, a user creating atarget group or administering a target group may seek to add additionalusers to the target group. To more easily identify users to add to thetarget group, the user invitation module 230 identifies a set ofcandidate users for a user in the target group to invite to the targetgroup. Based on characteristics of the user in the target group,characteristics of the candidate users and/or characteristics of thetarget group, the user invitation module 230 selects one or more of thecandidate users for recommendation.

A user in the target group may explicitly request recommendations forusers to add to the target group via a user interface or may receiverecommendations from the user invitation module 230 responsive toperforming an action within the social networking system 100. Forexample, the user joining the target group causes the user invitationmodule 230 to recommend additional users for the user to invite to thetarget group. Similarly, a user in the target group may interact with anobject in the social networking system 100, such as a group pageassociated with the target group, and the user invitation module 230provides user recommendations responsive to the interaction. Otherexample actions include becoming friends with another user, “liking” asocial networking system object, following a social networking systempage, interacting with social networking system content offsite, and thelike. Alternatively, the social networking system 100 includes a userinterface configured to request and display recommendations users tojoin a group based on input from a user in the group.

The user invitation module 230 identifies the target group based on theuser requesting a recommendation. For example, based on a request for arecommendation from a user or an action by a user, the user invitationmodule 230 identifies the target group. Generally, the target group is agroup having the user as a member, although the target group may be agroup with which the user is not a member but is instead merelyassociated or affiliated with. For example, a user may attend TheUniversity of Miami but not be a member of the Miami Hurricanes footballteam fan group; however, because the user and the Miami Hurricanesfootball team fan group include a common characteristic of “TheUniversity of Miami,” the user invitation module 230 may use the MiamiHurricanes football team fan group as the target group for recommendingadditional users to the user attending the University of Miami.

Any group having a user requesting a recommendation (a “requestinguser”) as a member, or otherwise associated with the requesting user,may be a target group for recommending additional users to therequesting user. For example, the user invitation module 230 may selectthe target group as the group that the target user most recently joinedor may select the target group as the group associated with the mostrecent action by the requesting user. As additional examples, the userinvitation module 230 selects the target group as the smallest or thelargest group to which the requesting user is a member, or selects thetarget as the group having the most average activity among members. Thetarget group may be a group that the requesting user created or manages.Any other suitable criteria may be used to select a target group.However, the requesting user may specify the target group whenrequesting a recommendation for additional users to join the targetgroup.

The user invitation module 230 identifies a set of candidate usersassociated with the requesting user. Recommendations for users to jointhe target group are made from the set of candidate users. In oneembodiment, the set of candidate users is all users that are explicitlyconnected to the requesting user. In another embodiment, the set ofcandidate users is a subset of users that connected to the requestinguser and satisfying one or more criteria (e.g., family members, friends,or co-workers of the target user; users with common interests, commongeographic information, common biographic information, commondemographic information, or any other common characteristic with therequesting user). The set of candidate users may include users that arenot connected to the requesting user, but have common characteristicswith the requesting user, such as common geographic, demographic, orbiographic information, common friends, common groups, and the like. Inone embodiment, candidate users are identified as described in U.S.application Ser. No. 12/857,533, titled “Suggesting Connections to aUser Based on an Expected Value of the Suggestion to the SocialNetworking System,” filed Aug. 16, 2010, the contents of which areincorporated herein by reference in their entirety.

One or more users from the set of candidate users are selected forrecommendation to the requesting user based on one or more criteria.Example criteria include: characteristics of the requesting user,characteristics of the target group, and characteristics of each user inthe set of candidate users. Such characteristics include geographiccharacteristics (such as a current or previous location, hometown,location check-in, location visited, and the like), a biographiccharacteristics (e.g., workplace, school, class year, career, major,class taken, sport participated in, age, gender, ethnicity, and thelike), hobbies or interests (e.g., a favorite sport or team, activity,celebrity, movie, actor, band, music genre, book, author, video game,board game, artist, and the like), political or religious views,philosophies, connected users (e.g., family, spouse, parent-child,sibling, co-workers, classmates, church members, friends, and the like),or any other characteristic suitable for use in selecting users forrecommendation. Characteristics of the requesting user, the targetgroup, and the users in the set of candidate users are retrieved fromthe social graph store 165 and from the group store 170.

The user invitation module 230 can select one or more candidate usersusing a variety of criteria. For example, a candidate user is selectedbased on the number of users connected to both the candidate user andthe requesting user. As an example, if three candidate users are to beselected for recommendation, the user invitation module 230 may selectthe three candidate users connected to the most common users as therequesting user. As another example, the user invitation module 230selects the candidate user with the highest number of members of thetarget group connected to the candidate user. Alternatively, acombination of these two factors may be used to select a candidate user.In one embodiment, a candidate user connected to the most common userswith the requesting user that are also members of the target group isselected.

In another embodiment, the user invitation module 230 determines a userscore for each candidate user and selects one or more candidate usersbased on the user scores. For example, the user invitation module 230selects one or more candidate users with the highest user scores. Asanother example, the user invitation module 230 selects one or morecandidate users with user scores equaling or exceeding a thresholdvalue. The user scores may be based on a combination of one or morefactors and the factors may also be weighted according to theirimportance or relevance.

One factor for calculating the user scores may be the number of commonusers connected to a candidate user and to the requesting user. Forexample, a user score for a first candidate user connected to 10 usersalso connected to the requesting user may be higher than a user scorefor a second candidate user connected to 2 users also connected to therequesting user. Another factor for calculating user scores may be thenumber of users that are members of the target group to which eachcandidate user is connected. For example, a user score for a firstcandidate user connected to 6 users that are members of the target groupis higher than a user score for a second candidate user connected to 3users that are members of the target group.

User scores may also be based on the affinities between the candidateusers and the requesting user. For example, a user score for a candidateuser that is the spouse of the requesting user may be higher than theuser score for a candidate user that is a co-worker of the requestinguser. The user scores may be based on common characteristics between therequesting user and the candidate users. For example, user scores may beproportional to the number or percentage of common biographical,demographical, or geographic information between each candidate user andthe requesting user, the number or percentage of common interests, andthe like. Similarly, user scores may be based on actions betweencandidate users and the requesting user. For example, a user score for acandidate user that communicates regularly with the requesting user maybe higher than a user score for a candidate user that does not ofteninteract with the target user.

In some embodiments, user scores may be based on common characteristicsbetween candidate users and the target group. For example, if a targetgroup is associated with particular subject matter, user scores forcandidate users associated with the subject matter may be higher thanuser scores for candidate users not associated with the subject matter.As an example, if a target group is associated with the state ofMinnesota, user scores for users listing Minnesota as a hometown, as acurrent city or previous city, as an interest, and the like, may behigher than candidate scores for users not associated with Minnesota. Asan additional example, for a target group associated with the SanFrancisco Giants, candidate users identifying the Giants as a favoriteteam, listing baseball as an interest, checking into the Giants'baseball stadium, or performing other actions associated with the Giantsmay have higher user scores than candidate users not associated with theGiants. User scores may also be based on common characteristics betweencandidate users and other members of the target group. For example, auser score for a candidate user that attended the same school or thatworked for the same employer as several members of the target group ishigher than the user score for a candidate user without characteristicsin common with members of the target group.

One or more candidate users selected for recommending to the requestinguser are displayed to the requesting user. The number of candidate usersselected may be predetermined, may be based on a context of therequesting user within the social networking system 100, or may be basedon interface constraints of the social networking system 100. Forexample, if the requesting user accesses a social networking systeminterface used to recommend users to add to a target group, the numberof candidate users selected may be based on the amount of display spaceavailable in the interface. In one embodiment, additional candidateusers may be selected in response to the recommending user selecting apresented user for addition to the target group. Selected candidateusers may be displayed in any suitable manner. For example, one or moreof names, images, or other information associated with selectedcandidate users are presented. Additional information may be presentedalong with the selected candidate users, such as one or more inputs foradding a candidate user to the group, such as an “add user” link, or thelike.

If the recommending user selects a presented candidate user to add tothe target group, the selected candidate user is added to the targetgroup. The selected candidate user may subsequently elect to be removedfrom the target group. In one embodiment, after electing to be removedfrom the target group, the selected candidate user is excluded fromfuture consideration as a candidate user for the target group.Alternatively, subsequently computed user scores for the selectedcandidate user electing to be removed from the target group may bereduced to decrease the likelihood of the selected candidate user againbeing recommended to join the target group. Alternatively, if therecommending user selects a presented candidate user, the selectedcandidate user may be invited to the target group or may be added to thetarget group pending the selected candidate user's approval of theaddition to the target group.

It should be noted that the principles described herein apply equally tocircumstances in which a target group has not yet been created. Forexample, candidate users can be identified and recommended to arecommending user as described above when the recommending user iscreating a group. In this example, the recommended candidate users canbe presented to the recommending user as potential users to add to thegroup that the recommending user is creating.

FIG. 4 is a flowchart of one embodiment of a process 400 for selecting auser to recommend adding to a group in a social networking system. Arequesting user is identified 405. The requesting user may be a userthat explicitly requests recommendations for users to add to a targetgroup, or may be a user performing an action in the social networkingsystem 100 that triggers a request for recommendations of users to addto the target group. In one embodiment, the target group is selected 410based characteristics of the requesting user or based on one or moreinputs received from the requesting user. For example, the target groupmay be a group having the requesting user as a member, may be the groupmost recently joined by the requesting user, may be the group mostrecently interacted with by the requesting user, may be the group havingthe largest number of members and that includes the target user, or maybe selected 410 using any other suitable criteria.

A set of candidate users associated with the requested user isidentified 420. In one embodiment, the set of candidate users includesusers connected to the requesting user. The set of candidate users mayinclude users connected to the requesting user and sharing one or morecommon characteristics with the requesting user, or may include usershaving specified types of connections to the requesting user. In someembodiments, the set of candidate users includes users having commoncharacteristics with the requesting user but that are not connected tothe requesting user. One or more characteristics of the target group,the requesting user, and/or the set of candidate users are identified430. Examples of characteristics of candidate users and/or therequesting user include biographic, demographic, or geographicinformation, interests, connections to additional users, groupsincluding the user, and the like. Example characteristics of the targetgroup include the group's subject matter, group members, and the like.

Based on the identified characteristics, one or more candidate users areselected 440 for recommendation to the requesting user. In oneembodiment, the candidate users are selected 440 based on the number ofcommon users connected to each candidate user and to the requesting userand/or based on the number of users connected to each candidate userthat are members of the target group. In one embodiment, a user score iscomputed for each candidate user based on one or more of: thecharacteristics of the candidate users, the characteristics of thetarget user, and/or the characteristics of the target group. Based onthe user scores, one or more candidate users are selected 440, asdescribed above in conjunction with FIG. 2.

Selected candidate users are presented to the requesting user. Forexample, the selected candidate users are displayed by a socialnetworking system interface, for instance within a social networkingsystem or external to the social networking system (using a socialnetworking system plug-in or similar technology). The requesting usermay select one or more of the presented candidate users to add to thetarget group, and the selected presented candidate users areautomatically be added to the target group. Alternatively, the selectedpresented candidate users are invited to the target group and added tothe target group if they accept the invitation.

Recommending a Group to Create

The social networking system 100 may also assist a user in creating anew group by recommending groups to create based on commoncharacteristics between users. The group creation recommendation module240 identifies a common characteristic between a creating user and oneor more other users and recommends creating a group associated with thecommon characteristic. The creating user may explicitly requestrecommendations for group creation from the social networking system 100by interacting with a group creation recommendation input.Recommendations for group creation may alternatively be automaticallyprovided based on one or more actions by the creating user in the socialnetworking system 100. In one embodiment, the creating creates a firstgroup, which causes the group creation recommendation module 240 torecommend the creation of a second group, which may be a sub-group ofthe first group.

To recommend a new group to create, the group creation recommendationmodule 240 identifies a set of users associated with the creating user.For example, the set of users includes any users connected to thecreating user, or includes users connected to the creating user by oneor more specified types of connections. In one embodiment, the set ofusers may include users having one or more characteristic in common withthe creating user but not connected to the creating user. Additionalusers can be added to the set of users, such as users with one or morecharacteristics in common with other users in the set of users but thatare not necessarily connected to the creating user.

One or more common characteristics between the creating user and one ormore users in the set of users are selected or identified. Any commoncharacteristic between the creating user and at least one user in theset of users may be selected. Examples of common characteristicsinclude: a common geographic characteristic (such as a current orprevious location, hometown, location check-in, location visited, andthe like), a common biographic characteristic (e.g., workplace, school,class year, career, major, class taken, sport participated in, age,gender, ethnicity, and the like), a common hobby or interest (e.g., afavorite sport or team, activity, celebrity, movie, actor, band, musicgenre, book, author, video game, board game, artist, and the like), acommon political or religious view, a common philosophy, a commonconnection type (e.g., family, spouse, parent-child, sibling,co-workers, classmates, church members, friends, and the like), or anyother characteristic suitable for a group's subject matter. It should benoted that characteristics of users may not be explicit, and may insteadbe inferred using dark tagging as described above.

In one embodiment, the creating user selects the one or more commoncharacteristics. Alternatively, the one or more common characteristicsare identified based on information associated with the creating userand users in the set of users. For example, a characteristic common tothe creating user and users in the set of users having the highestaffinity with the creating user. As described above, affinities betweenusers may be represented by a coefficient associated with an edgebetween nodes representing the user and the creating user in the socialgraph store 165. In one embodiment, a characteristic common to thecreating user and users in the set of users having at least a thresholdaffinity with the creating user is selected. For example, acharacteristic common to the creating user and family members of thecreating user in the set of users.

As another example, a characteristic common to the creating user and atleast a threshold number of users in the set of users is selected. Insome embodiments, characteristics common to the creating user and usersin the set of users are prioritized and the prioritization is used toselect one or more common characteristics. For example, familialrelationships common to the creating user and users in the set of usersmay have a higher priority than a favorite movie common to the creatinguser and users in the set of users; in this example, the common familialrelationship is selected as a common characteristic rather than thecommon favorite movie. Prioritization of common characteristics may bebased on stored data, and the highest priority characteristic orcharacteristics common to the creating user and one or more users in theset of selected users may be selected.

A selected common characteristic is used as the subject matter for agroup recommended by the group creation recommendation module 240 forcreation by the creating user. The create group recommendation module240 may also recommend a title for the recommended group based on theselected common characteristic. For example, if the selected commoncharacteristic is the movie “Pulp Fiction,” the title “Pulp FictionFans” may be recommended. As another example, if the selected commoncharacteristics are classmates at “Post Falls High School” and afavorite sports team of the “Chicago Cubs,” the title “Post Falls HighSchool Alumni Chicago Cubs Fans” may be recommended.

The group creation recommendation module 240 may identify and presentadditional users for addition to the group recommended for creation. Theadditional users may be identified from the set of users having theselected common characteristic with the creating user. Users having theselected common characteristic with the creating user but not in the setof users may also be identified as additional users. For example, thegroup creation recommendation module 240 recommends the creation of agroup to the creating user via a group creation interface and displaysadditional users to invite to the group, using the group creationinterface, if the creating user creates the recommended group.Information identifying the additional users, such as user names orimages, may be presented via the group creation interface. In oneembodiment, one or more identified additional users are automaticallyadded or invited to the recommended group if it is created. In thisembodiment, the group creation recommendation module 240 may allow thecreating user to prevent adding or inviting selected additionalidentified users to the group.

Group customization options may be presented to the creating user when arecommended group is created. Examples of group customization optionsinclude: changing the group title, adding or removing members to or fromthe group, inviting users to the group, providing descriptiveinformation about the group, customizing group communication options,creating or modifying a group page, uploading objects (such as photos orvideos) to the group, and the like. In one embodiment, one or morecustomization options may be automatically performed based oncharacteristics of the creating user and/or characteristics of usersadded to or invited to the group.

In one embodiment, the group creation recommendation module 240determines whether an existing group is related to the selected one ormore common characteristics before recommending the creation of a newgroup. For example, if the selected common characteristic is the movie“Pulp Fiction,” the group creation recommendation module 240 determinesif a group associated the movie “Pulp Fiction” is in the group store 170and recommends that the creating user join an existing group if one isin the group store 170. In one embodiment, the group creationrecommendation module 240 and the join group recommendation module 220exchange data, with the join group recommendation module 220 determiningwhether a group associated with the selected common characteristicalready exists and notifying the group creation recommendation module240 of the determination results.

FIG. 5 is a flowchart of an embodiment of a process 500 for recommendinga group creation by a social networking system user. The group creationrecommendation module 240 identifies 505 the creating user based on arequest for a recommendation received from the creating user or based onone or more interactions between a user and the social networking system100.

A set of users associated with the creating user are identified 510 fromthe social graph store 165. For example, the set of users includes usersconnected to the creating user and/or includes users sharing one or morecharacteristics with the creating user. One or more characteristicscommon to the creating user and one or more of the users in the set ofidentified users are selected 520, as further described above. Forexample, the selected common characteristic may be a characteristic thatis common to the most users in the set of identified users, may be acommon characteristic having a highest priority, may be a characteristiccommon to the users in the set of identified users having the highestaffinity with the creating user, or can be selected based on any othercriteria.

Based on the selected common characteristic or characteristics, a groupto be created is recommended 530 to the creating user. The groupcreation recommendation may be presented to the creating user via acreate group interface. For example, a potential title for the group maybe displayed along with one or more additional users sharing theselected common characteristic to add or invite to the group. In oneembodiment, the additional users are identified based on theiraffinities to the creating user. For example, affinities between theusers associated with the creating user and the creating user aredetermined and users associated with the creating user having thehighest affinities or having affinities of at least a threshold areselected as additional users to invite to the group. The recommendedgroup is created responsive to an input from the creating user to createthe group. In one embodiment, group configuration options, as describedabove, may be presented to the creating user after the group is created.

Recommending a Group to Join or Create Based on Answered Questions

In some embodiments, the social networking system 100 may requestinformation from a target user 105 and use the information to recommenda group for the target user 105 to join or to create. For example, thesocial networking system 100 presents the target user 105 with one ormore questions and uses answers to the questions to recommend a group tojoin or to create. The group question module 250 includes one or morequestions that are presented to a target user 105 and recommends a groupto the target user based on received answers to the questions. Questionsfrom the group question module 250 may be presented to the target user105 responsive to an explicit request by the target user 105 forquestions or based on interactions with the social networking system 100by the target user 105. For example, the target user 105 joins a firstgroup, causing the group question module 250 to present the target userwith questions for recommending additional groups to the target user105.

The group question module 250 may present questions using a questioninterface or using any suitable notification channel. For example,questions may be presented as stories within a news feed for the targetuser 105, as messages sent to the target user 105, as recommendedactions for the target user to perform 105, or as other suitablenotification techniques. Answers may be presented along with questions,allowing the target user 105 to select an answer. Alternatively, thetarget user 105 may enter text answers to presented questions.

Questions presented by the group question module 250 identifycharacteristics of the target user 105 to recommend one or more groupsto the target user 105. In one embodiment, the questions are presentedin a specified sequence to progressively obtain more detailedinformation about the target user 105. For example, questions can promptthe target user 105 to provide answers identifying biographicinformation associated with the target user (such as a current or formerworkplace or school, a class year, a major, career, sport participatedin, team played on, age, gender, ethnicity, and the like), geographicinformation associated with the target user (such as a current orprevious location, hometown, location checked-in to, location visited,and the like), a hobby or interest (such as a favorite sport or team,activity, celebrity, movie, actor, band, music genre, book, author,video game, board game, artist, and the like) or any othercharacteristic.

The questions presented to the target user 105 may be based at least inpart on the context of the target user within the social networkingsystem 100. In one embodiment, if the target user 105 joins a firstgroup, questions presented to the target user 105 are related to thesubject matter of the first group. For example, if a target user 105joins a group associated with the “University of Washington,” the groupquestion module 250 provides questions associated with attending auniversity, such as “What class year are you?” or “What major are you?”.If the context of the target user 105 within the social networkingsystem 100 is more generic (e.g., the target user 105 is not a member ofa group), the group question module 250 presents questions related tocharacteristics of the target user 105, such as information in a userprofile of the target user 105, information related to characteristicsof users connected to the target user 105, or other suitablecharacteristics associated with the target user 105.

The group question module 250 may present the target user 105 with aseries of questions, where successive questions are related topreviously asked questions. In one embodiment, questions presented tothe target user 105 become more specific in scope, allowing the groupquestion module 105 to identify a particular characteristic. Forexample, if a target user 105 joins a group related to baseball, a firstquestion may prompt the target user 105 to identify a favorite MajorLeague Baseball team and a second question may prompt the target user105 to identify a favorite player on the identified favorite team. Thegroup question module 250 may recommend a group based on an answer toany question in the series of questions.

When presenting questions to the target user 105, the group questionmodule 250 may present predetermined answers along with a question ormay present an input for the target user 105 to manually specify ananswer. Predetermined answers to a question may be based on commonlyreceived answers to the question, based on characteristics associatedwith the target user 105, or based on any other suitable criteria. Thegroup question module 105 may present one question at a time to thetarget user 105, or may present multiple questions to the target user105 at a time.

Answers received from the target user 105 may be associated with aparticular subject matter, such as people, places, things, or conceptsassociated with nodes in the social graph stored in the social graphstore 165. If the group question module 250 provides answers along witha question, the subject matter associated with the answers may bepredetermined. For answers provided by the target user 105, the groupquestion module 250 may compare the provided answer to nodes in thesocial graph store 165 to determine the subject matter associated withthe provided answer. For example, the group question module 250 compareskeywords in the provided answer with keywords associated with socialgraph nodes. In one embodiment, a target user 105 may identify subjectmatter associated with a provided answer using a tag or other metadata.

Upon receiving one or more answers from the target user 105, the groupquestion module 250 identifies one or more groups associated with thereceived answers. Subject matter associated with the received answers isused to identify groups that are associated with the same, or similar,subject matter. For example, if the target user 105 selects answersidentifying “baseball” as a favorite sport and “the San FranciscoGiants” as a favorite baseball team, one or more groups associated withone or more of “baseball” and “the San Francisco Giants” may beidentified. As another example, if the target user 105 provides answersindicating the target user 105 goes to San Diego State University,studies Biology, is in the class of 2014, and lives in Tenochca Hall,the group question module 250 retrieves groups associated with one ormore of: San Diego State University, the subject of Biology, the classof 2014, and Tenochca Hall from the social graph store 165 and/or thegroup store 170. In one embodiment, groups are identified by identifyinggroup nodes connected to subject matter nodes associated with receivedanswers from the social graph store. Groups may also be identified byidentifying groups recommended to or joined by other users answeringquestions similarly to the target user 105.

One or more identified groups associated with the received answers areselected for recommendation to the target user 105. Various criteria maybe used to select an identified group for recommending to the targetuser 105. Examples of criteria include: group size, group creationdates, users connected to the target user 105 that are members of thegroup, group characteristics, target user characteristics, or othersuitable criteria. If the group question module 250 is unable toidentify one or more groups associated with received answers, the groupquestion module 250 may recommend that the target user 105 create agroup based on the received answers. The group question module 250 maycommunicate with the group creation recommendation module 240 torecommend a group for creation, as further described above.

One or more groups recommended for the target user 105 by the groupquestion module 205 may be displayed to the target user 105 in a socialnetworking system interface or presented to the user by any othersuitable notification channel. In one embodiment, the target user 105interacts with the displayed groups to join a recommended group.Alternatively, the target user may be automatically added to one or morerecommended groups or may be automatically invited to one or morerecommended groups.

FIG. 6 is one embodiment of a process 600 for recommending a group for asocial networking system user to join based on answers to presentedquestions. The group question module 250 provides 605 a target user withone or more questions. In one embodiment, the questions are provided 605responsive to the group question module 250 receiving a request forquestions from the target user. Alternatively, the questions areprovided 605 in response to actions performed by the target user in thesocial networking system. One or more predefined answers may bepresented 605 along with the questions, allowing the target user toselect from the predefined answers or an input allowing the target userto manually specify an answer may be presented 605. In one embodiment,predetermined answers are each associated with particular subject matterto simplify identification of a group associated with an answer.

Characteristics of the target user are identified from the target user'sanswer to the presented questions. For example, answers to the questionsidentify geographic characteristics, biographic characteristics,demographic characteristics, hobbies, interests, or other suitablecharacteristics of the target user. The questions presented may be basedon the context of the target user within the social networking system100. For example, the presented questions are based on one or more of:the target user joining a group, the target user browsing a socialnetworking system page, the target user's characteristics, the targetuser's membership in groups, or other suitable information associatedwith the target user. In one embodiment, the target user is presented605 a series of questions that are successively more specific in scope,as described above, to identify a particular characteristic of thetarget user can be identified.

The group question module 250 receives 610 answers to the providedquestions from the target user and identifies 620 one or more groupsbased on the received answers. For received answers associated with aparticular subject matter, the group question module 250 determines 620whether the group store 170 includes one or more groups associated withthe particular subject matter. For answers that are not associated withsubject matter (such as answers provided by the target user but notassociated with subject matter by the target user), the group questionmodule 250 compares the received answers with subject matter stored inthe social networking system 100 to determine 620 if groups associatedwith the subject matter are included in the group store 170. In oneembodiment, keywords extracted from the answers are compared to keywordsassociated with subject matter in the social networking system 100.After identifying subject matter associated with an answer, a groupassociated with the subject matter is identified using a mapping betweensubject matter and groups mapping, identifying groups associated withkeywords matching keywords associated with the subject matter or usingany other suitable method.

If one or more groups associated with the received answers are includedin the group recommendation store 170, the group question module 250recommends 630 one or more of the groups to the target user. In oneembodiment, if the group question module 250 determines 620 that thegroup store 170 does not include a group associated with the receivedanswers, one or more groups are recommended 640 to the target user forcreation based on the received answers. Recommendations for joining orcreating a group may be presented to the target user through an anysuitable communication channel, as described above.

Summary

The foregoing description of the embodiments of the invention has beenpresented for the purpose of illustration; it is not intended to beexhaustive or to limit the invention to the precise forms disclosed.Persons skilled in the relevant art can appreciate that manymodifications and variations are possible in light of the abovedisclosure.

Some portions of this description describe the embodiments of theinvention in terms of algorithms and symbolic representations ofoperations on information. These algorithmic descriptions andrepresentations are commonly used by those skilled in the dataprocessing arts to convey the substance of their work effectively toothers skilled in the art. These operations, while describedfunctionally, computationally, or logically, are understood to beimplemented by computer programs or equivalent electrical circuits,microcode, or the like. Furthermore, it has also proven convenient attimes, to refer to these arrangements of operations as modules, withoutloss of generality. The described operations and their associatedmodules may be embodied in software, firmware, hardware, or anycombinations thereof.

Any of the steps, operations, or processes described herein may beperformed or implemented with one or more hardware or software modules,alone or in combination with other devices. In one embodiment, asoftware module is implemented with a computer program productcomprising a computer-readable medium containing computer program code,which can be executed by a computer processor for performing any or allof the steps, operations, or processes described.

Embodiments of the invention may also relate to an apparatus forperforming the operations herein. This apparatus may be speciallyconstructed for the required purposes, and/or it may comprise ageneral-purpose computing device selectively activated or reconfiguredby a computer program stored in the computer. Such a computer programmay be stored in a non-transitory, tangible computer readable storagemedium, or any type of media suitable for storing electronicinstructions, which may be coupled to a computer system bus.Furthermore, any computing systems referred to in the specification mayinclude a single processor or may be architectures employing multipleprocessor designs for increased computing capability.

Embodiments of the invention may also relate to a product that isproduced by a computing process described herein. Such a product maycomprise information resulting from a computing process, where theinformation is stored on a non-transitory, tangible computer readablestorage medium and may include any embodiment of a computer programproduct or other data combination described herein.

Finally, the language used in the specification has been principallyselected for readability and instructional purposes, and it may not havebeen selected to delineate or circumscribe the inventive subject matter.It is therefore intended that the scope of the invention be limited notby this detailed description, but rather by any claims that issue on anapplication based hereon. Accordingly, the disclosure of the embodimentsof the invention is intended to be illustrative, but not limiting, ofthe scope of the invention, which is set forth in the following claims.

What is claimed is:
 1. A method for recommending users to invite to asocial networking system group comprising: receiving, at a socialnetworking system server from a client device, a request from a user ofa social networking system identifying the social networking systemgroup maintained by the social networking system, the group including aset of users of the social networking system; accessing, by the socialnetworking system, a user profile associated with the user of the socialnetworking system, the user profile identifying one or morecharacteristics of the user; determining, by the social networkingsystem server from the user profile, a set of candidate users connectedto the user and not included in the identified group; determining, bythe social networking system server, a user score for each of thecandidate users, a user score for a candidate user based on each of oneor more characteristics of the candidate user, a likelihood that theuser will invite the candidate user when suggested, a likelihood thatthe candidate user will join the group when invited by the user, and anamount of activity of the user within the identified group; selecting,by the social networking system server, a candidate user associated witha user score greater than a threshold value from the set of candidateusers; and presenting, by the social networking system server via theclient device, the selected candidate user to the user within a socialnetworking system interface displayed by the client device.
 2. Themethod of claim 1, wherein a characteristic of the candidate usercomprises one or more characteristics common to the user and thecandidate user.
 3. The method of claim 2, wherein selecting thecandidate user from the set of candidate users further comprises:selecting a candidate user connected to a highest number ofcharacteristics common to the user.
 4. The method of claim 2, whereinthe user score for the candidate user is proportional to a number ofcharacteristics common to the user and the candidate user.
 5. The methodof claim 2, wherein the user score for the candidate user isproportional to a percentage of characteristics common to the user andthe candidate user.
 6. The method of claim 1, wherein a characteristicof the candidate user comprises a frequency of interaction between thecandidate user and the user.
 7. The method of claim 6, wherein the userscore for the candidate user is proportional to the frequency ofinteraction between the candidate user and the user.
 8. The method ofclaim 1, wherein the group identified by the request includes the user.9. The method of claim 1, wherein the group identified by the request isa group the user recently joined.
 10. The method of claim 1, wherein oneor more characteristics of the candidate user are selected from a groupconsisting of: geographic information associated with the candidateuser, biographic information associated with the candidate user, one ormore interests of the candidate user, one or more additional usersconnected to the candidate user, and one or more groups including thecandidate user.
 11. The method of claim 1, wherein a characteristic ofthe candidate user comprises one or more characteristics of thecandidate user associated with one or more characteristics of the group.12. The method of claim 1, further comprising: receiving an input fromthe user identifying the selected candidate user; and adding theselected user to the group responsive to the input.
 13. The method ofclaim 1, further comprising: adding the selected user to the group. 14.A non-transitory computer readable storage medium storing executablecomputer instructions that, when executed by a hardware processor, causethe hardware processor to perform steps comprising: receiving, at asocial networking system server from a client device, a request from auser of a social networking system identifying a social networkingsystem group maintained by the social networking system, the groupincluding a set of users of the social networking system; accessing, bythe social networking system, a user profile associated with the user ofthe social networking system, the user profile identifying one or morecharacteristics of the user; determining, by the social networkingsystem server from the user profile, a set of candidate users connectedto the user and not included in the identified group; determining, bythe social networking system server, a user score for each of thecandidate users, a user score for a candidate user based on each of oneor more characteristics of the candidate user, a likelihood that theuser will invite the candidate user when suggested, a likelihood thatthe candidate user will join the group when invited by the user, and anamount of activity of the user within the identified group; selecting,by the social networking system server, a candidate user associated witha user score greater than a threshold value from the set of candidateusers; and presenting, by the social networking system server via theclient device, the selected candidate user to the user within a socialnetworking system interface displayed by the client device.
 15. A systemfor recommending users to invite to a social networking system groupcomprising: a non-transitory computer readable storage medium storingexecutable instructions that, when executed, perform steps comprising:receiving, at a social networking system server from a client device, arequest from a user of a social networking system identifying the socialnetworking system group maintained by the social networking system, thegroup including a set of users of the social networking system;accessing, by the social networking system, a user profile associatedwith the user of the social networking system, the user profileidentifying one or more characteristics of the user; determining, by thesocial networking system server from the user profile, a set ofcandidate users connected to the user and not included in the identifiedgroup; determining, by the social networking system server, a user scorefor each of the candidate users, a user score for a candidate user basedon each of one or more characteristics of the candidate user, alikelihood that the user will invite the candidate user when suggested,a likelihood that the candidate user will join the group when invited bythe user, and an amount of activity of the user within the identifiedgroup; selecting, by the social networking system server, a candidateuser associated with a user score greater than a threshold value fromthe set of candidate users; and presenting, by the social networkingsystem server via the client device, the selected candidate user to theuser within a social networking system interface displayed by the clientdevice; and a hardware processor to execute the instructions.